1. Field of the Invention
This invention relates generally to gasket welders and more particularly to a gasket welder wherein a vacuum is applied to the outer surface of the gasket, thereby allowing the gasket to retain its original shape while being welded to another gasket.
2. Description of the Prior Art
In various Industries, there has always been the need to weld two plastic parts together to form a single article of manufacture. When the two thin walled parts to be joined are flexible, there is the problem of maintaining the profile of the parts, especially if they are hollow, while they are being welded.
In the door and window industry, this problem has recently become more acute. With the higher demand for increased performance, it has been necessary to upgrade the quality of weatherstripping available. One type of weatherstripping commonly used for doors and windows is a TPE (thermal plastic elastomer) weatherstrip which has a hollow portion. In addition, a variety of weatherstrip materials are utilized, such as PVC. The hollow portion is advantageous for many purposes, but it does raise the problem of how to effectively join two pieces of weatherstripping having the hollow profile. During the manufacturing process, when the two weatherstrips are joined, quite often the weatherstripping is deformed during the manufacturing operation and a less than perfect joint is formed. This creates a potential for air or water leakage around the improperly formed joint.
Many different welding machines have been used to join such weatherstrips having a hollow, flexible construction. One such machine is the DS four-point seal welding machine ADS-4 by Dieter Schuster GmbH. Such a welding machine is able to weld four corners of a frame at one time, thereby providing for a completed gasket in one operation. However, such a welding machine does not allow for the consistent high quality welding of a gasket having a thin wall, flexible or hollow construction.
The present invention provides for a new jig which may be used with such welding machines to overcome the problems associated with the prior art and provide for a means of maintaining the profile of the weatherstripping material while it is being welded.